2638765 has 4 divisors (see below), whose sum is σ = 3166524. Its totient is φ = 2111008.

The previous prime is 2638747. The next prime is 2638771. The reversal of 2638765 is 5678362.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 556516 + 2082249 = 746^2 + 1443^2 .

It is a cyclic number.

It is not a de Polignac number, because 2638765 - 2⁹ = 2638253 is a prime.

It is a d-powerful number, because it can be written as 2¹¹ + 6³ + 3¹² + 8⁷ + 7 + 6⁵ + 5³ .

It is a Duffinian number.

2638765 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 263872 + ... + 263881.

It is an arithmetic number, because the mean of its divisors is an integer number (791631).

2^2638765 is an apocalyptic number.

It is an amenable number.

2638765 is a deficient number, since it is larger than the sum of its proper divisors (527759).

2638765 is an equidigital number, since it uses as much as digits as its factorization.

2638765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527758.

The product of its digits is 60480, while the sum is 37.

The square root of 2638765 is about 1624.4275914918. The cubic root of 2638765 is about 138.1869097926.

It can be divided in two parts, 2638 and 765, that added together give a triangular number (3403 = T₈₂).

The spelling of 2638765 in words is "two million, six hundred thirty-eight thousand, seven hundred sixty-five".